Yahoo! Inc.global Internet services company based in Sunnyvale, Calif. The company was founded in 1994 by Jerry Yang and David Filo, graduate students at Stanford University in California. Yahoo! boasts more than 100 million users per month, and it provides users with online utilities, information, and access to other Web sites.

Yahoo!, which includes features such as a search engine, an e-mail service, a directory, and a news branch, began as a simple collection of Yang and Filo’s favourite Web sites. It was initially called “Jerry and David’s Guide to the World Wide Web,” but, as the site grew in popularity, it was renamed Yahoo!, an acronym for “Yet Another Hierarchical Officious Oracle.” Incorporated in 1995, Yahoo acquired various companies such as Rocketmail and ClassicGames.com, which eventually became Yahoo! Mail and Yahoo! Games, respectively. As one of the major players in the dot-com frenzy of the late 1990s, Yahoo! managed to survive the collapse of many Internet-based companies in 2001–02, but it sustained heavy economic losses.

Yahoo! has battled Google—a major competitor in the search engine industry—for many years in an attempt to claim a larger share of the market. However, despite Yahoo!’s release of its Yahoo! Instant Messenger, its buyout of the Internet photo network Flickr, and its inclusion of myriad other features, many of its rivals have endured. In February 2008 the Microsoft Corporation offered to buy Yahoo! for $44.6 billion, but this proposal was rejected by Yahoo!, and Microsoft then rescinded its offer. However, negotiations between the companies continued, and on July 28, 2009, an agreement was reached in which Yahoo! would use Microsoft’s search engine, Bing, for its Web site and would handle premium advertisements for Microsoft’s Web site, an arrangement scheduled to last for 10 years.